Over the past half century two principal types of cooling systems have been employed in the bosh, belly and stack of blast furnaces. These two cooling systems have been cooling plates and cooling staves, each with their own advantages and disadvantages.
Conventional cooling plates are tongue shaped coolers which protrude through a single hole in the steel furnace shell and stick into the vessel on average approximately 24 inches and are approximately 24 inches wide. Such plates are securely fastened to the steel shell and the plates are connected to an external cooling source. These cooling plates are often positioned in staggered rows around the furnace so that the distance from the center of one plate cooler to the center of the next plate cooler would be 15 to 48 inches horizontally and 15 to 36 inches vertically. The spaces between these plate coolers on the inside of the furnace are typically filled with a brick material to form a solid refractory system against the cooling plates and inside furnace wall. Cooling systems using these plates have the disadvantage that close bricks are more effectively cooled, while those located at some distance are subject to greater corrosion. Due to the non-uniform cooling, these plates do not offer as much shell protection as a cooling stave design.
Staves are elements placed between the inner side of the steel shell of a furnace and the refractory lining. The staves are typically formed with a series of tubes to carry a heat transfer fluid, such as water. The staves can cool a furnace uniformly as they may be installed to have almost complete steel shell coverage. Typical stave coolers are approximately 30″ to 50″ wide by 48″ to 144″ tall. These staves are typically bolted to the furnace wall and may have small gaps between them to allow for installation.
A major disadvantage of such a stave/brick construction is that due to the closeness to each other when installed in a furnace, such staves must be removed from the furnace to allow the bricks to be slid out of the stave channels whenever the stave/brick construction needs to be rebuilt or repaired, either in-whole or in-part. Removing such staves from the furnace is necessitated because bricks cannot be removed or inserted into stave channels through the front face of stave. Additionally, pins to support the stave, separate thermocouple shell protrusions, water pipe protrusions, and flexible compensators are typically required.
In order to overcome the disadvantages associated with typical furnace cooling plates and cooling staves, it would be desirable to provide a cooling plate or stave that combines the advantages of conventional cooling plates and cooling staves while eliminating most or all of the disadvantages of conventional cooling plates and conventional cooling staves.
It would also be desirable to provide a cooling plate that may be inserted and installed from the outside of the furnace through a single opening in the steel shell of the furnace, and supported by a secure fastening on the outside of the furnace shell while on the inside of the furnace shell, the cooling plate is disposed as a stave between the inner side of the shell and the refractory lining. It would also be desirable to provide a cooling plate where the lower end of one plate is supported by the top of a lower plate and/or one or more sides of the one plate are supported additionally by one or more sides of one or more adjacent plates. It would be desirable further to provide a cooling plate wherein an associated thermocouple may be installed within the plate cooler stave. Further, it would be desirable to provide a cooling plate that can be installed from outside the furnace yet provide for uniform cooling of the furnace like a stave while eliminating the numerous pins, thermocouple shell protrusions, water pipe protrusions and flexible compensators typically required for the installation and operation of conventional staves and/or cooling plates.
These and other advantages of the invention will be appreciated by reference to the detailed description of the preferred embodiment(s) that follow.